Rentgen tube, De-Broile wavelength and Compton effect

1. The problem statement, all variables and given/known data
A Roentgen tube produces radiation with minimal wavelength. (λM)
De-Broglie Wavelength of electrons reaching Anode is λE.
Assuming electrons are not relativistic, what is the proper relation between wavelengths
λM, λE and Compton wavelength (λC)

2. Relevant equations
λE=h/p
λC=h/mc
I am not sure, minimal wavelength - what that is ?
This is multiple answers question, but any of the answers don't make sense to me.

3. The attempt at a solution
I think that relation between λC and λM can be wrote down through Compton effect:
λC=λE-λM=h/mc(1-cosα)
However, there is no angle given, so I cam confused about what to do?